Skip to main content
Log in

From Streaks to Spots and on to Turbulence: Exploring the Dynamics of Boundary Layer Transition

  • Published:
Flow, Turbulence and Combustion Aims and scope Submit manuscript

Abstract

“...an eerie type of chaos can lurk just behind a facade of order, and yet deep inside the chaos lurks an even eerier type of order.” Douglas Hofstadter

Bypass transition to turbulence in boundary layers is examined using linear theory and direct numerical simulations (DNS). First, the penetration of low-frequency free-stream disturbances into the boundary layer is explained using a model problem with two time scales, namely the shear and wall-normal diffusion. The simple model provides a physical understanding of the phenomenon of shear sheltering. The second stage in bypass transition is the amplification of streaks. Streak detection and tracking algorithms were applied to examine the characteristics of the streak population inside the boundary layer, beneath free-stream turbulence. It is demonstrated that simple statistical averaging masks the wealth of streak amplitudes in transitional flows, and in particular the high-amplitude, relatively rare events that precede the onset of turbulence. The third stage of the transition process, namely the secondary instability of streaks, is examined using secondary instability analysis. It is demonstrated that two types of instability are possible: An outer instability arises near the edge of the boundary layer on the lifted, low-speed streaks. An inner instability also exists, and has the appearance of a near-wall wavepacket. The stability theory is robust, and can predict the particular streaks which are likely to undergo secondary instability and break down in transitional boundary layers beneath free-stream turbulence. Beyond the secondary instability, turbulent spots are tracked in DNS in order to examine their characteristics in the subsequent non-linear stages of transition. At every stage, we compare the findings from linear theory to the empirical observations from direct solutions of the Navier-Stokes equations. The complementarity between the theoretical predictions and the computational experiments is highlighted, and it leads to a detailed view of the mechanics of transition.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Andersson, P., Berggren, M., Henningson, D.S.: Optimal disturbances and bypass transition in boundary layers. Phys. Fluids 11(1), 134–150 (1999)

    Article  MathSciNet  MATH  Google Scholar 

  2. Andersson, P., Brandt, L., Bottaro, A., Henningson, D.S.: On the breakdown of boundary layer streaks. J. Fluid Mech. 428, 29–60 (2001)

    Article  MathSciNet  MATH  Google Scholar 

  3. Barkley, D., Blackburn, H.M., Sherwin, S.J.: Direct optimal growth analysis for time steppers. Int. J. Num. Meth. Fluids 57, 1435–1458 (2008)

    Article  MathSciNet  MATH  Google Scholar 

  4. Brandt, L., Schlatter P., Henningson, D.S.: Transition in boundary layers subject to free-stream turbulence. J. Fluid Mech. 517, 167–198 (2004)

    Article  MathSciNet  MATH  Google Scholar 

  5. Brandt, L., de Lange, H.C.: Streak interactions and breakdown in boundary layer flows. Phys. Fluids 20, 024107 (2008)

    Article  Google Scholar 

  6. Butler, K.M., Farrell, B.F.: Three-dimensional optimal disturbances in viscous shear flow. Phys. Fluids A 4, 1637–1650 (1992)

    Article  Google Scholar 

  7. Cantwell, B., Coles, D., Dimotakis, P.: Structure and entrainment in the plane of symmetry of a turbulent spot. J. Fluid Mech. 87(04), 641–672 (1978)

    Article  Google Scholar 

  8. Durbin, P.A., Zaki, T.A., Liu, Y.: Interaction of discrete and continuous boundary layer modes to cause transition. Int. J. Heat Fluid Flow 30, 403–410 (2009)

    Article  Google Scholar 

  9. Durbin, P., Wu, X.: Transition Beneath Vortical Disturbances. Ann. Rev. Fluid Mech. 39, 107–128 (2007)

    Article  MathSciNet  Google Scholar 

  10. Emmons, H.W.: The laminar-turbulent transition in a boundary layer. Part i. J. Aero. Sci. 18, 490–498 (1951)

    Article  MathSciNet  MATH  Google Scholar 

  11. Fasel, H.F.: Numerical investigation of the interaction of the Klebanoff-mode with a Tollmien–Schlichting wave. J. Fluid Mech. 450, 1–33 (2002)

    Article  MathSciNet  MATH  Google Scholar 

  12. Goldstein, M.E., Wundrow, D.W.: On the environmental realizability of algebraically growing disturbances and their relation to Klebanoff modes. Theor. Comput. Fluid Dyn. 10, 171–186 (1998)

    Article  MATH  Google Scholar 

  13. Görtler, H.: Instabilität laminarer Grenzschichten an konkaven Wänden gegenüber gewissen dreidimensionalen Störungen. Z. Angew. Math. Mech. 21, 250–252 (1941)

    Article  MathSciNet  Google Scholar 

  14. Grosch, C.E., Salwen, H.: The stability of steady and time-dependent plane Poiseuille flow. J. Fluid Mech. 34, 177–205 (1968)

    Article  MATH  Google Scholar 

  15. Grosch, C.E., Salwen, H.: The continuous spectrum of the Orr–Sommerfeld equation. Part 1. The spectrum and the eigenfunctions. J. Fluid Mech. 68, 33–54 (1978)

    Article  MathSciNet  Google Scholar 

  16. Hack, M.J.P., Zaki, T.A.: The continuous spectrum of time-harmonic shear layers. Phys. Fluids 24, 034101 (2012)

    Article  Google Scholar 

  17. Hack, M.J.P., Zaki, T.A.: Streak instabilities in boundary layers beneath free-stream turbulence. J. Fluid Mech. (2013, under review)

  18. Hultgren, L.S., Gustavsson, L.H.: Algebraic growth of disturbances in a laminar boundary layer. Phys. Fluids 24, 1000–1004 (1981)

    Article  MATH  Google Scholar 

  19. Hunt, J.C.R., Durbin, P.A.: Perturbed shear layers. Fluid Dyn. Res. 24, 375–404 (1999)

    Article  MathSciNet  MATH  Google Scholar 

  20. Jacobs, R.G., Durbin, P.A.: Shear sheltering and the continuous spectrum of the Orr-Sommerfeld equation. Phys. Fluids 10, 2006–2011 (1998)

    Article  MathSciNet  MATH  Google Scholar 

  21. Jacobs, R.G., Durbin, P.A.: Simulations of bypass transition. J. Fluid Mech. 428, 185–212 (2001)

    Article  MATH  Google Scholar 

  22. Kleiser, L., Zang, T.A.: Numerical simulation of transition in wall-bounded shear flows. Ann. Rev. Fluid Mech. 23, 495–537 (1991)

    Article  Google Scholar 

  23. Landahl, M.T.: A note on an algebraic instability of inviscid parallel shear flows. J. Fluid Mech. 98, 243–251 (1980)

    Article  MathSciNet  MATH  Google Scholar 

  24. Leib, S.J., Wundrow, W., Goldstein, M.e.: Effect of free-stream turbulence and other vortical disturbances on a laminar boundary layer. J. Fluid Mech. 380, 169–203 (1999)

    Article  MathSciNet  MATH  Google Scholar 

  25. Liu, Y., Zaki, T.A., Durbin, P.A.: Boundary layer transition by interaction of discrete and continuous modes. J. Fluid Mech. 604, 199–233 (2008)

    Article  MathSciNet  MATH  Google Scholar 

  26. Liu, Y., Zaki, T.A., Durbin, P.A.: Floquet analysis of secondary instability of boundary layers distorted by Klebanoff streaks and Tollmien–Schlichting waves. Phys. Fluids 20, 124102 (2008)

    Article  Google Scholar 

  27. Luchini, P.: Reynolds-number-independent instability of the boundary layer over a flat surface: optimal perturbations. J. Fluid Mech. 404, 289–309 (2000)

    Article  MathSciNet  MATH  Google Scholar 

  28. Mandal, A.C., Venkatakrishnan, L., Key, J.: A study on boundary-layer transition induced by free-stream turbulence. J. Fluid Mech. 660, 114–146 (2010)

    Article  MATH  Google Scholar 

  29. Matsubara, M., Alfredsson, P.: Disturbance growth in boundary layers subjected to free-stream turbulence. J. Fluid Mech. 430, 149–168 (2001)

    Article  MATH  Google Scholar 

  30. Nagarajan, S., Lele, S. K., Ferziger, J. H.: Leading-edge effects in bypass transition. J. Fluid Mech. 572, 471–504 (2007)

    Article  MATH  Google Scholar 

  31. Nolan, K., Walsh, E.J.: Particle image velocimetry measurements of a transitional boundary layer under free stream turbulence. J. Fluid Mech. 702, 215–238 (2012)

    Article  MATH  Google Scholar 

  32. Nolan, K., Zaki, T.A.: Conditional sampling of transitional boundary layers in pressure gradients. J. Fluid Mech. 728, 306–339 (2013)

    Article  Google Scholar 

  33. Ovchinnikov, V., Choudhari, M.M., Piomelli, U.: Numerical simulations of boundary-layer bypass transition due to high-amplitude free-stream turbulence. J. Fluid Mech. 613, 135–169 (2008)

    Article  MathSciNet  MATH  Google Scholar 

  34. Phillips, O.M.: Shear-flow turbulence. Ann. Rev. Fluid Mech. 1, 245–264 (1969)

    Article  Google Scholar 

  35. Rosenfeld, M., Kwak D., Vinokur M.: A fractional step solution method for the unsteady incompressible Navier-Stokes equations in generalized coordinate systems. J. Comput. Phys. 94, 102–137 (1991)

    Article  MATH  Google Scholar 

  36. Saric, W.S., Reed, H.L., White, E.B.: Stability and transition of three-dimensional boundary layers. Ann. Rev. Fluid Mech. 35, 413–440 (2003)

    Article  MathSciNet  Google Scholar 

  37. Schlatter, P., Brandt, L., de Lange, H.C., Henningson, D.A.: On streak breakdown in bypass transition. Phys. Fluids 20, 101505 (2008)

    Article  Google Scholar 

  38. Schrader, L.-U., Brandt, L., Zaki, T.A.: Receptivity, instability and breakdown of Görtler flow. J. Fluid Mech. 682, 362–396 (2011)

    Article  MATH  Google Scholar 

  39. Swearingen, J.D., Blackwelder, R.F.: The growth and breakdown of streamwise vortices in the presence of a wall. J. Fluid Mech. 182, 255–290 (1987)

    Article  Google Scholar 

  40. Vaughan, N.J., Zaki, T.A.: Stability of zero-pressure-gradient boundary layer distorted by unsteady Klebanoff streaks. J. Fluid Mech. 681, 116–153 (2011)

    Article  MATH  Google Scholar 

  41. Westin, K.J.A., Boiko, A.V., Klingmann, B.G.B., Kozlov, V.V., Alfredsson, P.H.: Experiments in a boundary layer subjected to freestream turbulence. Part I: boundary layer structure and receptivity. J. Fluid Mech. 281, 193–218 (1994)

    Article  Google Scholar 

  42. Wu, X., Durbin, P.A.: Evidence of longitudinal vortices evolved from distorted wakes in a turbine passage. J. Fluid Mech. 446, 199–228 (2001)

    MATH  Google Scholar 

  43. Zaki, T.A., Durbin, P.A.: Mode interaction and the bypass route to transition. J. Fluid Mech. 531, 85–111 (2005)

    Article  MathSciNet  MATH  Google Scholar 

  44. Zaki, T.A., Durbin, P.A.: Continuous mode transition and the effects of pressure gradient. J. Fluid Mech. 563, 357–388 (2006)

    Article  MathSciNet  MATH  Google Scholar 

  45. Zaki, T.A., Saha, S.: On shear sheltering and the structure of vortical modes in single and two-fluid boundary layers. J. Fluid Mech. 626, 111–148 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  46. Zaki, T.A., Wissink, J.G., Durbin, P.A., Rodi, W.: Direct computations of boundary layers distorted by migrating wakes in a linear compressor cascade. Flow, Turb. & Comb. 83, 307–322 (2009)

    Article  MATH  Google Scholar 

  47. Zaki, T.A., Wissink, J.G., Rodi, W., Durbin, P.A.: Direct numerical simulations of transition in a compressor cascade: the influence of free-stream turbulence. J. Fluid Mech. 665, 57–98 (2010)

    Article  MATH  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Tamer A. Zaki.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Zaki, T.A. From Streaks to Spots and on to Turbulence: Exploring the Dynamics of Boundary Layer Transition. Flow Turbulence Combust 91, 451–473 (2013). https://doi.org/10.1007/s10494-013-9502-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10494-013-9502-8

Keywords

Navigation